Diagnostic accuracy of the new Xpert MTB/RIF Ultra for tuberculosis disease: a preliminary systematic review and meta-analysis

Abstract Objectives Due to the poor sensitivity of Xpert MTB/RIF assay for the detection of tuberculosis (TB) in some conditions, the re-engineered Xpert MTB/RIF Ultra (Xpert Ultra) has been developed and recommended by World Health Organization (WHO) since 2017. We performed a systematic review and meta-analysis here to assess the accuracy of Xpert Ultra for the detection of TB and rifampicin (RIF) resistance. Methods Medline (via PubMed), Embase (via OvidSP), ISI Web of Science, the Cochrane Central Register of Controlled Trials, and Scopus were screened for original articles. Summary sensitivity and specificity were calculated with a bivariate mixed- effects model. A Fagan nomogram was used to assess the clinical utility. The sources of heterogeneity were investigated by meta-regression and subgroup analyses. Results 16 studies were identified and the summary diagnostic accuracy of Xpert Ultra for the diagnosis of TB were a sensitivity of 87.2% (95% CI: 82.5–90.8%) and a specificity of 96.5% (95% CI: 95.1–97.5%). For RIF resistance detection, sensitivity was 95.1% (95% CI: 91.6–97.2%) and specificity was 98.9% (95% CI: 97.6–99.5%). Meta-regression showed the category of population, TB prevalence, the reference standard, sample state, sample type and study design that were attributed to the heterogeneity. Subgroup analyses found good performance of Xpert Ultra in settings with a low TB burden. Conclusions As a rapid and highly sensitive test for TB detection and simultaneous detection of RIF resistance, Xpert Ultra exhibit viable alternative in sensitivities in both PTB and EPTB, and also shows a good performance in RIF resistance detection.